Under a proposal, suspected terrorists would be tried and held in a hybrid 'courtroom within a detention facility' at an existing U.S. maximum-security prison.

WASHINGTON — The Obama administration could transfer Guantanamo inmates to be tried and detained at a hybrid military-civilian prison in the United States as part of a proposal being examined by U.S. security agencies, officials said Sunday.

The proposal for creating a combined detention and trial facility for Guantanamo inmates in an existing U.S. maximum-security prison is likely to be controversial. Congress has opposed bringing detainees to the United States, despite President Obama's vow to close the naval prison in Cuba by January.

Officials at the White House, Justice Department and other agencies confirmed that the idea of a "courtroom within a detention facility" was being examined. But officials emphasized that nothing had been decided and that other options were under consideration by a multi-agency task force studying detainee issues.

"No decisions have been made," White House spokesman Ben LaBolt said.

A spokesman at the Justice Department, which is leading the task force, also said that no decisions had been made about whether to establish such a facility. An Obama administration official said the task force was considering a wide array of options and was expected to make its recommendations as early as this month.

The proposal was first reported Sunday by the Associated Press.

The 229 inmates who remain at Guantanamo Bay are accused of belonging to Al Qaeda, allied extremist networks or the Taliban. U.S. officials hope to prosecute some of them in federal court and others before military commissions.

But complex questions must be resolved as part of the process of shutting down the base. About 60 prisoners have been cleared for release but cannot be sent to their homelands because of fears they would be persecuted.

The administration has been trying to persuade European allies to take in some in that group, although the U.S. has not accepted any. Several European governments have been reluctant because of the cost, political sensitivity and potential security risks.

U.S. law enforcement officials are also wrestling with decisions about the fate of suspected terrorists who are considered too dangerous to release but cannot be prosecuted because evidence is weak or has been tainted by alleged abuse. Those include Khalid Shaikh Mohammed, the self-proclaimed mastermind of the Sept. 11 attacks.

When Congress passed a war-funding bill this year, it omitted the $80 million Obama requested to close Guantanamo. The measure also bars the administration from releasing detainees to freedom in the United States, at least until Sept. 30. It would, however, allow the administration to bring certain prisoners to U.S. jails for pretrial detention.

The Obama administration is looking at civilian and military detention facilities in the United States.

"It is no secret the administration is considering bringing the detainees to the U.S.," said a government official, who asked to remain anonymous because he was not authorized to discuss the internal deliberations.

The task force has been looking at a number of unused or underused civilian facilities, including a soon-to-be-closed maximum-security prison in Michigan. In fact, a source close to the deliberations said the courtroom-within-a-prison plan was floated in May by Michigan Republicans, including former Gov. John Engler, suggesting a site in their state.

The Associated Press reported Sunday that the facility was the Standish maximum security prison in eastern Michigan. But that option has been rejected, at least for now, the government official told The Times.

The Pentagon has also examined the detention facilities at Ft. Leavenworth, Kan.; Camp Pendleton; and the Charleston, S.C., naval brig. But the government official said those were not designed to be supermax facilities.

"None of them are ideal options," the official said.

Congressional Republicans have said it would be dangerous and reckless to bring the Guantanamo detainees to the United States. During the last several years, Sen. Sam Brownback (R-Kan.) has waged a campaign to block any plans for using Leavenworth. He and Rep. Lynn Jenkins (R-Kan.) have scheduled a news conference for today to repeat their opposition, according to the AP.

In an opinion piece last year on LATimes.com, Brownback argued that the Leavenworth disciplinary barracks lacks the space, security and infrastructure to house Guantanamo inmates. He also said jailing alleged foreign terrorists with U.S. military personnel would violate international law.

"Though it is a maximum-security facility, 80% of its inmates have some freedom of movement through the prison," Brownback wrote. "In only one wing of the barracks does security meet requirements for detainees. That wing is far too small even to force-fit Guantanamo's detainees. Moreover, because the Department of Defense lacks other available maximum-security space, we would be unable to transfer military prisoners out of Ft. Leavenworth to make room for the Guantanamo detainees."